A control system has been proposed in the past in which the position of a work implement is automatically adjusted in a work vehicle such as a bulldozer or a grader. For example, Japanese Patent No. 5,247,939 discloses digging control and grading control. In digging control, the position of the blade is automatically adjusted so that the load on the blade will match a target load. In grading control, the position of the blade is automatically adjusted so that the cutting edge of the blade moves along a design terrain indicating the target shape to be dug.